/**
 * @(#)QuaquaLazyActionMap.java
 *
 * Copyright (c) 2008 by the original authors of JHotDraw and all its
 * contributors. All rights reserved.
 *
 * You may not use, copy or modify this file, except in compliance with the 
 * license agreement you entered into with the copyright holders. For details
 * see accompanying license terms.
 */

package org.jhotdraw.gui.plaf.palette;

import java.lang.reflect.*;
import javax.swing.*;
import javax.swing.plaf.*;

/**
 * QuaquaLazyActionMap.
 * 
 * @author Werner Randelshofer
 * @version $Id: PaletteLazyActionMap.java 717 2010-11-21 12:30:57Z rawcoder $
 */
public class PaletteLazyActionMap extends ActionMapUIResource {
	/**
	 * Object to invoke <code>loadActionMap</code> on. This may be a Class
	 * object.
	 */
	private transient Object loader;

	/**
	 * Installs an ActionMap that will be populated by invoking the
	 * <code>loadActionMap</code> method on the specified Class when necessary.
	 * <p>
	 * This should be used if the ActionMap can be shared.
	 * 
	 * @param c
	 *            JComponent to install the ActionMap on.
	 * @param loaderClass
	 *            Class object that gets loadActionMap invoked on.
	 * @param defaultsKey
	 *            Key to use to defaults table to check for existing map and
	 *            what resulting Map will be registered on.
	 */
	static void installLazyActionMap(JComponent c, Class loaderClass, String defaultsKey) {
		ActionMap map = (ActionMap) UIManager.get(defaultsKey);
		if (map == null) {
			map = new PaletteLazyActionMap(loaderClass);
			UIManager.getLookAndFeelDefaults().put(defaultsKey, map);
		}
		SwingUtilities.replaceUIActionMap(c, map);
	}

	/**
	 * Returns an ActionMap that will be populated by invoking the
	 * <code>loadActionMap</code> method on the specified Class when necessary.
	 * <p>
	 * This should be used if the ActionMap can be shared.
	 * 
	 * @param loaderClass
	 *            Class object that gets loadActionMap invoked on.
	 * @param defaultsKey
	 *            Key to use to defaults table to check for existing map and
	 *            what resulting Map will be registered on.
	 */
	static ActionMap getActionMap(Class loaderClass, String defaultsKey) {
		ActionMap map = (ActionMap) UIManager.get(defaultsKey);
		if (map == null) {
			map = new PaletteLazyActionMap(loaderClass);
			UIManager.getLookAndFeelDefaults().put(defaultsKey, map);
		}
		return map;
	}

	private PaletteLazyActionMap(Class loader) {
		this.loader = loader;
	}

	public void put(Action action) {
		put(action.getValue(Action.NAME), action);
	}

	@Override
	public void put(Object key, Action action) {
		loadIfNecessary();
		super.put(key, action);
	}

	@Override
	public Action get(Object key) {
		loadIfNecessary();
		return super.get(key);
	}

	@Override
	public void remove(Object key) {
		loadIfNecessary();
		super.remove(key);
	}

	@Override
	public void clear() {
		loadIfNecessary();
		super.clear();
	}

	@Override
	public Object[] keys() {
		loadIfNecessary();
		return super.keys();
	}

	@Override
	public int size() {
		loadIfNecessary();
		return super.size();
	}

	@Override
	public Object[] allKeys() {
		loadIfNecessary();
		return super.allKeys();
	}

	@Override
	public void setParent(ActionMap map) {
		loadIfNecessary();
		super.setParent(map);
	}

	@SuppressWarnings("unchecked")
	private void loadIfNecessary() {
		if (loader != null) {
			Object ldr = loader;

			loader = null;
			Class klass = (Class) ldr;
			try {
				Method method = klass.getDeclaredMethod("loadActionMap", new Class[] { PaletteLazyActionMap.class });
				method.invoke(klass, new Object[] { this });
			} catch (NoSuchMethodException nsme) {
				assert false : "LazyActionMap unable to load actions " + klass;
			} catch (IllegalAccessException iae) {
				assert false : "LazyActionMap unable to load actions " + iae;
			} catch (InvocationTargetException ite) {
				assert false : "LazyActionMap unable to load actions " + ite;
			} catch (IllegalArgumentException iae) {
				assert false : "LazyActionMap unable to load actions " + iae;
			}
		}
	}
}
